Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: Tealight on September 27, 2016, 09:29:22 AM

Title: Albedo-Warming Potential
Post by: Tealight on September 27, 2016, 09:29:22 AM
The Albedo-Warming Potential is an attempt to quantify the additional warming from a lower ice cover at the poles. At the moment these calculations don't include cloud cover, therefore it is called "Warming Potential" and not actual warming. However, over six-month weather tends to average out and warm areas correlate well with low ice extend in September. The basis of all calculations is a self-developed global surface radiation model and NSIDC Sea Ice Concentration data.
It is in essence a much better version of my “Quantifying albedo effect / Rating daily area values” topic. In order to present the results better I created my own website and only use links on the forum. If I update my calculations all changes will be applied to this first post too and not scattered across several posts. 

Link to my website CryosphereComputing:
https://cryospherecomputing.tk/awp.html (https://cryospherecomputing.tk/awp.html)

former website
https://sites.google.com/site/cryospherecomputing/warming-potential (https://sites.google.com/site/cryospherecomputing/warming-potential)


The following images are all cumulative results from the last day of the melt season. The end of the astronomical summer to be precise. For daily Animations click on the link below the year. All daily values are also available on my website.

All anomalies are calculated against the 2007-2016 sea ice concentration average.
Red indicates lower albedo and above average warming.
Blue indicates higher albedo and below average warming.
One extra day of peak insulation on open ocean is about 20 MJ/m2.
One extra month of peak insulation on open ocean is about 600 MJ/m2.

2007
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2007)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEa1RyOHhrb3ZubEE&export=download)

2008
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2008)
(https://drive.google.com/uc?id=0B1HTR0ONiUmEb29wZXFhMy1wNXM&export=download)

2009
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2009)
(https://drive.google.com/uc?id=0B1HTR0ONiUmETHNVNTU2d25hOXc&export=download)

2010
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2010)
(https://drive.google.com/uc?id=0B1HTR0ONiUmERGl4ZXFrOG5XRFE&export=download)

2011
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2011)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEdmotVmhfUDFiVHM&export=download)

2012
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2012)


(https://drive.google.com/uc?id=0B1HTR0ONiUmEclhhaEo2TUYyRTg&export=download)


2013
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2013)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEQjJvd3hDZDVrbE0&export=download)

2014
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2014)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEcnliZWtfUC1objg&export=download)

2015
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2015)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEOWhVdFZaTWdJN0E&export=downlo)

2016
Daily Animation (https://sites.google.com/site/cryospherecomputing/warming-potential/2016)

(https://drive.google.com/uc?id=0B1HTR0ONiUmEdVctTUJLRkVwUVU&export=download)

Pan Arctic Graphs:

(https://drive.google.com/uc?id=0B1HTR0ONiUmEQ2RzVndDS0d0aFE&export=download)
(https://drive.google.com/uc?id=0B1HTR0ONiUmERjdlQ2pKVzlDb0k&export=download)

Regional graphs:

https://sites.google.com/site/cryospherecomputing/warming-potential/regional-graphs (https://sites.google.com/site/cryospherecomputing/warming-potential/regional-graphs)


Global surface radiation model details:
The model calculates the incoming solar energy per day per m2 for all latitudes between 40N and 90N (0.2 degree steps). Considered are solar zenith angles, the atmospheric reduction (Air mass), Projection effect and water albedo for every 15min interval. If a grid cell has 55% ice concentration, then it is treated as a water area 55% the size of the grid cell.


NSIDC Sea Ice Concentration details:
   Ice concentration average: 2007-2016
   Pole hole ice concentration is calculated from a 2-pixel wide ring around the hole
   Lake ice is ignored to reduce noise
   Pixel Area corrected
   warming potential for each individual pixel (max. 0.44-pixels off from pixel center)

NSIDC Data
Cavalieri, D., C. Parkinson, P. Gloersen, and H. J. Zwally. 1996, updated yearly. Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data, Version 1. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.http://dx.doi.org/10.5067/8GQ8LZQVL0VL. (http://dx.doi.org/10.5067/8GQ8LZQVL0VL.)
Title: Re: Albedo-Warming Potential
Post by: Random_Weather on September 27, 2016, 11:48:57 AM
Its really only the potential, if you use the cloud fraction: https://climexp.knmi.nl/select.cgi?id=someone@somewhere&field=cru_cld would be more pracise

Title: Re: Albedo-Warming Potential
Post by: seaicesailor on September 27, 2016, 12:27:35 PM
Awesome!
Title: Re: Albedo-Warming Potential
Post by: oren on September 27, 2016, 01:32:29 PM
Beautiful. This is one of the big impacts of sea ice loss - quantifying it is highly important.
What are the start and end dates for the calculation?
Assuming you mean to continue this wonderful resource in the future, preferably the baseline should be fixed and not incorporate each new year into the average.

Since you mentioned "the poles" at the top of your post, I am wondering if you have any plans to do Antarctica as well? Deniers keep talking their BS of how global sea ice is fine even when the Arctic is at minimum. But of course, winter sea ice at the south pole does not compensate for missing summer sea ice at the north pole in terms of albedo and energy imbalance.
Title: Re: Albedo-Warming Potential
Post by: Tealight on September 27, 2016, 07:33:16 PM
Its really only the potential, if you use the cloud fraction: https://climexp.knmi.nl/select.cgi?id=someone@somewhere&field=cru_cld would be more pracise
Yes cloud cover is the next logical step, but there are lots of different cloud types. Some are warming, some are cooling the surface and even professional climate scientists rate clouds of the biggest uncertainty in climate models. The chance that I get it perfectly right is very low.


Beautiful....
That was my first thought too.

The start and end dates are 20th march and 21st september. This is the whole astronomical summer. When you follow the link to the daily animations you can see the dates as well.

I used the 2007-2016 average because:
1. In 2007 the Arctic changed significantly and never went back to its previous state(muli-year ice fraction)
2. Since 2008 the pole hole is much smaller ( less approximation errors)
3. 10 years is a significant number with a special name (decade)

Calculating the same for the Antarctic is no problem. I just need to download all concentration files/masks and change a few lines of code. What timeperiod do you have in mind? For Antarctica there isn't a polehole and I'm not aware of any significant changes.

Title: Re: Albedo-Warming Potential
Post by: oren on September 27, 2016, 09:39:24 PM
Same time period should be fine.
I think Antarctic solar pattern is somewhat different due to variation of distance from the sun. I'm sure you've got that straightened out.
Title: Re: Albedo-Warming Potential
Post by: Tealight on September 30, 2016, 10:32:30 PM
Same time period should be fine.
I think Antarctic solar pattern is somewhat different due to variation of distance from the sun. I'm sure you've got that straightened out.

The variable solar constant from our eliptical orbital is considered for the Arctic as well. I can't exactly consider the same time period because the Antarctic melting season is shifted by half a year. For a complete decade I have to start with 2006/07 and end with 2015/16.

For the Antarctic the melting season doesn't align as nicely with the astronomical summer like the arctic does. Should I just ignore it to keep both models consistent?
southern summer: 22 sep - 20 march
southern melting season: 22 sep - 24 feb
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ (http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/)

Title: Re: Albedo-Warming Potential
Post by: oren on September 30, 2016, 11:55:45 PM
I'm hardly an expert on this subject (or any subject on this forum TBH), but it seems to me the astronomical summer should be the appropriate period, as this is approximately when insolation is the major driver of heat accumulation, winning over heat loss to space.
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 03, 2016, 02:40:06 AM
I added the typical graphs to my website as and the first post well.
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 18, 2016, 02:54:33 AM
I did some minor improvements and accounted for the fact that snow/ice doesn't have an albedo of 1.00 All values are now compared to snow and roughly 20% smaller than before.

On my Website I also added regional graphs using NSIDC regions:
https://sites.google.com/site/cryospherecomputing/warming-potential/regional-graphs

As Oren requested I did the same calculations for Antarctica as well. I will post a seperate thread there soon.
Title: Re: Albedo-Warming Potential
Post by: oren on October 18, 2016, 11:31:08 AM
Thanks Tealight for your great work. The graphs are amazing. I think this year's results are now reflected in the very poor refreeze. Too much heat was accumulated too early.
Title: Re: Albedo-Warming Potential
Post by: seaicesailor on October 18, 2016, 08:11:39 PM
Tealight, are you already factoring in the cloudiness of each day, (and hence you get these large day-to-day variations or they respond to other cause?).
Looks really awesome. Really showing some reasons why 2016 is ending in super late refreezing of the whole Pacific side.
Title: Re: Albedo-Warming Potential
Post by: seaicesailor on October 18, 2016, 08:19:08 PM
Wow 2016 is/was another black swan!
https://sites.google.com/site/cryospherecomputing/warming-potential/graphs
Title: Re: Albedo-Warming Potential
Post by: marcel_g on October 18, 2016, 09:26:38 PM
Thanks for these very interesting graphs Tealight!

I was wondering about the units of the pan-Arctic chart that shows the different regions together:
https://sites.google.com/site/cryospherecomputing/warming-potential/2016

Are the different regions weighted for area, or are the units just in KWh/M2?

If the latter, it would be really interesting to see a chart that multiplied the albedo cumulative forcing by the area of the region, and then put all the regions together, so we could see how the regions stack up relative to each other in terms of overall energy gain.
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 18, 2016, 11:37:56 PM
Thanks Tealight for your great work. The graphs are amazing. I think this year's results are now reflected in the very poor refreeze. Too much heat was accumulated too early.

Yes the spring heat is now heavily impacting the refreeze. In July I already predicted it on the "Quantifying albedo effect" topic.

... Most of 2016 high energy came during spring, when meltponds were absent. So mainly into increasing water temperature in the marginal ice zone or simply prevent refreezing. 2012 on the other hand had high anomalies during June-August. This was caused by melt ponds (high extent/area ratio) so mostly towards ice melt.

-------

Tealight, are you already factoring in the cloudiness of each day, (and hence you get these large day-to-day variations or they respond to other cause?).
Looks really awesome. Really showing some reasons why 2016 is ending in super late refreezing of the whole Pacific side.

I still didn't factor in cloud cover. What large day-to-day variations do talk about? On the daily graph are large jumps because each year starts heavy meltponding on different days and sometimes they partially refreeze. Warming due to low ice concentration is pretty consistent.


Thanks for these very interesting graphs Tealight!

I was wondering about the units of the pan-Arctic chart that shows the different regions together:
https://sites.google.com/site/cryospherecomputing/warming-potential/2016

Are the different regions weighted for area, or are the units just in KWh/M2?

The units on the link you are refrering to are in KWh/M2 as well. It is not weigthed for area, but it is corrected for individual pixel area.  I just updated these graphs to match the regional graph design.

Quote
If the latter, it would be really interesting to see a chart that multiplied the albedo cumulative forcing by the area of the region, and then put all the regions together, so we could see how the regions stack up relative to each other in terms of overall energy gain.

My calculations only compare energy gain relative to average sea ice cover and not overall energy gain per area. I believe it is more important to look in what regions a year has high warming than just comparing energy values. For example the Sea of Okhotsk and Hudson Bay have quite a large area and high ernergy values due to their lower latitudes, but they are almost irelevent for the September minimum. The Beaufort Sea and in general the whole Pacific side of the Arctic Ocean have relatively small areas, but are essential for a low September minimum.

Title: Re: Albedo-Warming Potential
Post by: seaicesailor on October 19, 2016, 12:12:24 AM

Tealight, are you already factoring in the cloudiness of each day, (and hence you get these large day-to-day variations or they respond to other cause?).
Looks really awesome. Really showing some reasons why 2016 is ending in super late refreezing of the whole Pacific side.

I still didn't factor in cloud cover. What large day-to-day variations do talk about? On the daily graph are large jumps because each year starts heavy meltponding on different days and sometimes they partially refreeze. Warming due to low ice concentration is pretty consistent.

Sorry I explained myself as poorly as I undestood it. The fluctuations I talk about are the ones present in your  plot I attach. It is due to daily concentration variations only then.
Title: Re: Albedo-Warming Potential
Post by: wili on October 19, 2016, 04:28:06 PM
Yes, thanks for these very important graphs and analysis, Tealight.

From this one, it looks as though we passed a crucial tipping point in 2010. I don't remember anyone noting this, even though it is arguably as important as the much discussed 'virtually ice free' moment.

(https://sites.google.com/site/cryospherecomputing/warming-potential/graphs/Arctic_Cumulative_Warming%20values.PNG)

Arctic albedo going from cooling influence to warming one seems like kind of a big deal, no??
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 30, 2016, 08:03:34 PM
I've seen on the Arctic News blog that the IPCC expresses the radiative forcing of CO2 in W/m2. To better compare my values with this one I converted my final cumulative energy values into W/m2 for the Summer and for the whole year.

On its own a doubling of CO2 would amount to a radiative forcing of 3.7 W/m2.

The table below shows the highest regional values for 2016 compared to the 2007-2016 average. Compared to the 1980s all values would be higher.

RegionBarents SeaKara SeaLaptev SeaBeaufort SeaUnit
Energy45.5852.85-58.7679.23kWh/m2
Summer10.2111.84-13.1617.75W/m2
Year5.206.03-6.709.04W/m2

So even if we half the values to account for cloud cover the albedo already has a higher impact than a doubling of CO2 would have.
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on October 31, 2016, 12:39:54 AM
I've seen on the Arctic News blog that the IPCC expresses the radiative forcing of CO2 in W/m2. To better compare my values with this one I converted my final cumulative energy values into W/m2 for the Summer and for the whole year.

On its own a doubling of CO2 would amount to a radiative forcing of 3.7 W/m2.

The table below shows the highest regional values for 2016 compared to the 2007-2016 average. Compared to the 1980s all values would be higher.

RegionBarents SeaKara SeaLaptev SeaBeaufort SeaUnit
Energy45.5852.85-58.7679.23kWh/m2
Summer10.2111.84-13.1617.75W/m2
Year5.206.03-6.709.04W/m2

So even if we half the values to account for cloud cover the albedo already has a higher impact than a doubling of CO2 would have.

Would we be able to calculate the negative impact of albedo changes due to additional NHEM snowcover during autumn?
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 31, 2016, 12:28:59 PM
Would we be able to calculate the negative impact of albedo changes due to additional NHEM snowcover during autumn?

Unlikely. The good thing about the ocean is that the surface can vary just between two well known states: water and ice
On Land there are too many ground types and trees keep the albedo low even if the ground is covered in snow. Below is a calculation of average image brightness for different terrain types. All land images are taken from Worldview on the 31/10/2016 near Lake Baikal.


Region         Brightness
Snow-free-plains.png      25.8   %
Snow-covered-plains.png      46.2   %
Snow-forest.png      36.6   %
seaice.png      86.3   %
Title: Re: Albedo-Warming Potential
Post by: Tigertown on October 31, 2016, 03:38:08 PM
Would we be able to calculate the negative impact of albedo changes due to additional NHEM snowcover during autumn?

Unlikely. The good thing about the ocean is that the surface can vary just between two well known states: water and ice
On Land there are too many ground types and trees keep the albedo low even if the ground is covered in snow. Below is a calculation of average image brightness for different terrain types. All land images are taken from Worldview on the 31/10/2016 near Lake Baikal.


Region         Brightness
Snow-free-plains.png      25.8   %
Snow-covered-plains.png      46.2   %
Snow-forest.png      36.6   %
seaice.png      86.3   %

How do what's considered snow-covered in today's terms compare to years in the past. Many times in the past, a snow covered plain would be so deep you couldn't tell where it ended, and it was blinding. This doesn't look very deep, which shows what bbr is saying to be true. A little snow doesn't have the Albedo of an old fashioned deep snow cover. Compare to the second image from 2011.(Not trying to argue with Tealight, who makes so many good posts, but just trying to show how things are changing)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on October 31, 2016, 03:49:43 PM
Would we be able to calculate the negative impact of albedo changes due to additional NHEM snowcover during autumn?

Unlikely. The good thing about the ocean is that the surface can vary just between two well known states: water and ice
On Land there are too many ground types and trees keep the albedo low even if the ground is covered in snow. Below is a calculation of average image brightness for different terrain types. All land images are taken from Worldview on the 31/10/2016 near Lake Baikal.


Region         Brightness
Snow-free-plains.png      25.8   %
Snow-covered-plains.png      46.2   %
Snow-forest.png      36.6   %
seaice.png      86.3   %

How do what's considered snow-covered in today's terms compare to years in the past. Many times in the past, a snow covered plain would be so deep you couldn't tell where it ended, and it was blinding. This doesn't look very deep, which shows what bbr is saying to be true. A little snow doesn't have the Albedo of an old fashioned deep snow cover. Compare to the second image from 2011.(Not trying to argue with Tealight, who makes so many good posts, but just trying to show how things are changing)


I get what you are saying but I think you inverted my position accidentally? In fact, the plains would have *deeper* snow now than other years enhancing the albedo.

See the below map of current depth anomalies...

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)

Now obviously we do not need exact calculations but if we could approximate the albedo impact of +2SD NHEM snowcover in Sep/Oct it would be very illuminating regarding what the *total* impact of near-ice-free Arctic is as despite popular perception, it does result in ++++snowcover anomalies across the NHEM, at least in autumn.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fpng%2Fdaily_dn%2F2016304.png&hash=9c922f31be0402ee4af3d1696d722a0b)

Would it be more feasible to do a basic average of base biome albedo for areas ~50N, compare with same biome + snowcover, then compare to previous yrs? I am highly suspicious that the albedo feedback from the autumnal snowcover anomalies this year may actually be even larger than what was accumulated on the other side due to the lack of sea ice this spring/summer/fall/yr in general...
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on October 31, 2016, 04:01:42 PM
PS... my very rough calculation is that we basically have a Canada's worth of surplus snowcover at the moment... that is about 6.5% of the global land surface area.

So basically, need to calculate the base albedo from 50N, what it is with snowcover, then the differential of this yr with what it would normally be... this is going to be a very large number  :-\

The considerations made a couple posts above re: differences for albedo depending on amount of snowcover is something I had not considered entirely but I think that given the trends we are seeing (not only more snowcover, but +++ depth), perhaps this can exacerbate things even further...
Title: Re: Albedo-Warming Potential
Post by: Tigertown on October 31, 2016, 04:12:27 PM
Excuse me if I am missing something here, but I thought the problem with feedback was from times when Albedo or reflectivity are low and thus things absorb more energy from the sun. I thought it to be a good thing to have a thick snow cover with high Albedo to reflect the energy back into space, considering clouds don't trap it and send it back.
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on October 31, 2016, 04:14:57 PM
Excuse me if I am missing something here, but I thought the problem with feedback was from times when Albedo or reflectivity are low and thus things absorb more energy from the sun. I thought it to be a good thing to have a thick snow cover with high Albedo to reflect the energy back into space, considering clouds don't trap it and send it back.
Yes, it is a good thing to have a thick snow cover with high albedo, but when that thick snowcover is double the size of what is used to be in extent (and also thicker), you can see how the reflectiveness issue leaves Earth with much less heat... technically we never left the ice age...!
Title: Re: Albedo-Warming Potential
Post by: Archimid on October 31, 2016, 04:37:33 PM
The increase in snow cover in October seems to be part of a larger trend. It was at the same levels as we are today during the 70's, then it drop down during the 80's  to pick back up again during the 00's. It seems like the same thing happened throughout the North hemisphere. For the spring months is the opposite. Snow cover has decreased steadily across the board.

The evidence for this is on the following page:
 https://www.ncdc.noaa.gov/sotc/global-snow/201503 (https://www.ncdc.noaa.gov/sotc/global-snow/201503)

Choose 2015 for the end year and switch between October and April to see the data for those months.

Notice that parity is achieved around March, with declining snow cover until July. I explain the increase of snow in october to much more water vapor due to climate change. That snow will melt really fast come next spring. Once the arctic has fully melted that snow will switch to rain, except for rare occasions.


Title: Re: Albedo-Warming Potential
Post by: Tigertown on October 31, 2016, 04:58:59 PM
The increase in snow cover in October seems to be part of a larger trend. It was at the same levels as we are today during the 70's, then it drop down during the 80's  to pick back up again during the 00's. It seems like the same thing happened throughout the North hemisphere. For the spring months is the opposite. Snow cover has decreased steadily across the board.

The evidence for this is on the following page:
 https://www.ncdc.noaa.gov/sotc/global-snow/201503 (https://www.ncdc.noaa.gov/sotc/global-snow/201503)

Choose 2015 for the end year and switch between October and April to see the data for those months.

Notice that parity is achieved around March, with declining snow cover until July. I explain the increase of snow in october to much more water vapor due to climate change. That snow will melt really fast come next spring. Once the arctic has fully melted that snow will switch to rain, except for rare occasions.
   Add to that the same type of blocking patterns that cause excessive rain in some places and droughts in others.
Title: Re: Albedo-Warming Potential
Post by: Tealight on October 31, 2016, 05:24:55 PM

How do what's considered snow-covered in today's terms compare to years in the past. Many times in the past, a snow covered plain would be so deep you couldn't tell where it ended, and it was blinding. This doesn't look very deep, which shows what bbr is saying to be true.

On snow cover maps this plains region was considered to have 5-10cm of snow. The forest image had 10-15cm snow according to the map. This shows our problem with insufficient data. If a region with thicker snow cover can have a lower albedo than a region with thinner snow cover then any calculation is just a guess into the blue.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fold.wetterzentrale.de%2Fpics%2FRnhemsnow.gif&hash=d3c86af1b7b1932252466916e6cf7fe5)

I attached a graph showing the daily energy value that gets absorbed by the ground for different albedos. If you compare these to the radiative losses it should be clear that they are a lot smaller and the difference comes out of the ground, lakes or from further south.

Edit: The atmosphere absorbs some energy as well. For total radiative balance the ground value should be multiplied by 1.1 or 1.2.

approx. radiative losses per day under clear sky
Celsius   kWh loss
+10       5.68
0            4.92
-10         4.24
-20         3.63
-30         3.09
-40         2.61

PS: Please don't use phrases like it is good or is bad. 
Title: Re: Albedo-Warming Potential
Post by: andy_t_roo on October 31, 2016, 07:41:54 PM
Once the sun goes down permanently in the north, the emissivity of water is a strong negative warning potential, due to the energy imbalance. Would it be possible to update charts to show the net effect of the unprecedented area of open water that currently exists?
Title: Re: Albedo-Warming Potential
Post by: magnamentis on October 31, 2016, 09:41:16 PM
Would we be able to calculate the negative impact of albedo changes due to additional NHEM snowcover during autumn?

Unlikely. The good thing about the ocean is that the surface can vary just between two well known states: water and ice
On Land there are too many ground types and trees keep the albedo low even if the ground is covered in snow. Below is a calculation of average image brightness for different terrain types. All land images are taken from Worldview on the 31/10/2016 near Lake Baikal.


Region         Brightness
Snow-free-plains.png      25.8   %
Snow-covered-plains.png      46.2   %
Snow-forest.png      36.6   %
seaice.png      86.3   %

just as a little "YES i agree" but: under circumstances water can have different colors up to light blue, red or green etc. algae, sedimentation and other factors which we cannot yet exclud to pop up in the future due to ever warming oceans. i have nothing specific in mind and don't know enough details but it has happened in the past that areas of seawater got "colored".

i'm referring to the "two states" of water as compared to "many states" of land, as mentioned that's in general mostly true but not absolutely true :-)
Title: Re: Albedo-Warming Potential
Post by: Tealight on November 01, 2016, 09:14:03 PM
Once the sun goes down permanently in the north, the emissivity of water is a strong negative warning potential, due to the energy imbalance. Would it be possible to update charts to show the net effect of the unprecedented area of open water that currently exists?

I'm not quite sure what you mean with "updating the charts". The net effect of open water is a completly different calculation. Do you mean the charts in my top post or in my "Reply #27" ?

I did some crude calculation of what the energy values mean for refreezing. The Beaufort for example had +80kWh at the end of September. With a clear sky loss 5kWh per day the extra energy could keep the ocean 16 days longer ice free than the 2007-2016 average. However the Beaufort was an extreme example and the Arctic currently receives plenty of heat from further south to keep the ocean open. On my area graph 2016 is about 17 days behind the average.

@magnamentis
You are of course right. Algae could develop on open ocean. Sediments are limited to the coastlines which are masked out by the NSIDC.

Title: Re: Albedo-Warming Potential
Post by: Hans on December 05, 2016, 07:01:47 PM
New study +14C in winter 2100:
Albedo impact is not largest Summer when the sun shines, but has a delayed impact in winter temperatures. See study by Richard Bintanja and Folmer Krikken of the KNMI: 'Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing' in http://www.nature.com/articles/srep38287 (http://www.nature.com/articles/srep38287). Expected annual average + 8C, but for winter +14C due to late refreeze and related changes in forcing... Ouch! + 14C ??? oh dear.... :-\

Is this what we see also now develloping?
Title: Re: Albedo-Warming Potential
Post by: Archimid on December 10, 2016, 11:58:02 AM
Hello. I know that my questions are sometimes stupid and I want to thank Tealight for answering them beautifully.  That said, here goes another one.

 Lately, I have been wondering, what would the maximum albedo warming potential be in a completely hypothetical situation of 0 arctic sea ice from March Equinox to September Equinox?

For example, If the arctic ocean was at 0C in March, with no ice cover, what would the potential  surface temperature be by September if all other considerations are ignored?

Title: Re: Albedo-Warming Potential
Post by: Buddy on December 10, 2016, 12:42:37 PM
If the albedo effect is delayed....I assume you mean the effect is delayed on the transfer of heat from the ocean to the atmosphere from the ocean is delayed.  So.....the additional heat that is now being absorbed by the southern oceans....the largest effect on the atmosphere will be during the Southern Hemispheres winter....which will be our summer (July, August, September).  Do I have that right?
Title: Re: Albedo-Warming Potential
Post by: Tealight on December 10, 2016, 01:04:21 PM
For example, If the arctic ocean was at 0C in March, with no ice cover, what would the potential  surface temperature be by September if all other considerations are ignored?

That an interesting question and not a stupid one. I can't tell you what the exact temperature will be, but I can run my simulation for zero ice extent. Most likely the temperature will be similar to the northern Baltic sea or the Barents sea just north of Norway.

I already did a simulation for a theoretical minimum of ice concentration from all years.
https://sites.google.com/site/cryospherecomputing/warming-potential/fanatsy-years

comparison of cumulative warming values at september equinox
2009 (coldest): -19.95
2007-2016 average: 0
2016 (warmest): 18.13
Minimum of Minima: 119.15
completly ice free: 301.07

@Buddy
Archimid was talking about the Arctic. I did run my model for this melting season in Antarctica and it is already in first place for cumulative value. That said I don't feel my model is as valuable for Antarctica as it is for the Arctic. I plan to add a daily updated page on my website for Albedo-Warming Potential as well. It would switch hemispheres in April and October to always show the correct melting season.
Title: Re: Albedo-Warming Potential
Post by: Buddy on December 10, 2016, 01:32:59 PM
@Archimid....I was just seeing if my thinking on the issue of albedo effect "lag time" was correct.  This is the first time when so much of BOTH ice sheets are gone....and it will be interesting to see what the SHORT TERM effects are on atmospheric warming.  I don't imagine it will be anything that any of us will like.
Title: Re: Albedo-Warming Potential
Post by: Archimid on December 11, 2016, 02:04:35 PM
That an interesting question and not a stupid one.

Phew, finally :)

 Thanks for the answer.

Quote
I can't tell you what the exact temperature will be, but I can run my simulation for zero ice extent. Most likely the temperature will be similar to the northern Baltic sea or the Barents sea just north of Norway.

Yeah, I see it better now. I looked at ocean temperatures around the peripheral seas and assumed an arctic without sea ice would be of similar temperature, but probably colder. That is of course assuming albedo is the only variable, which is not. I am starting  to believe it is the most important one. At least more significant than greenhouse gases.



Quote
comparison of cumulative warming values at september equinox
2009 (coldest): -19.95
2007-2016 average: 0
2016 (warmest): 18.13
Minimum of Minima: 119.15
completly ice free: 301.07


Yep that answers my question and produces other ones.

Quote
Minimum of Minima: 119.15


That is the minima from the 2007-2016 average, right? If so, it would be interesting to see the minimum of Minima from the 1980-2000 average. The difference between the two should be significant.
Title: Re: Albedo-Warming Potential
Post by: DavidR on December 12, 2016, 03:31:56 AM
@Archimid....I was just seeing if my thinking on the issue of albedo effect "lag time" was correct.  This is the first time when so much of BOTH ice sheets are gone....and it will be interesting to see what the SHORT TERM effects are on atmospheric warming.  I don't imagine it will be anything that any of us will like.

Given that there is very little albedo effect  in the Arctic for the next  month, I  don't think we will see much impact there. The Antarctic however is a different matter its currently 2 million below average and 3.7 million below 2014-2015
Title: Re: Albedo-Warming Potential
Post by: jdallen on December 12, 2016, 08:21:20 AM
Given that there is very little albedo effect  in the Arctic for the next  month...

<GUFFAWS LOUDLY>

David, you owe me a cloth to clean my screen.
Title: Re: Albedo-Warming Potential
Post by: Buddy on December 12, 2016, 01:16:32 PM
Quote
The Antarctic however is a different matter its currently 2 million below average and 3.7 million below 2014-2015

Yes....clearly now the impact during the southern hemisphere summer is going to be from the lack of ice in the southern oceans as I noted before.  And I have to believe it will be more than an insignificant amount.  With southern ice melt about 10% greater than normal........certainly this will have an effect on ocean warming....

Apparently there is someone else on the forum who doesn't understand that there is a quite significant amount of ice melt going on in the southern hemisphere.  Surprising really....:)

“Small minds just like small stones can never create giant waves.”


Title: Re: Albedo-Warming Potential
Post by: oren on December 12, 2016, 01:49:30 PM
...I did run my model for this melting season in Antarctica and it is already in first place for cumulative value. That said I don't feel my model is as valuable for Antarctica as it is for the Arctic. I plan to add a daily updated page on my website for Albedo-Warming Potential as well. It would switch hemispheres in April and October to always show the correct melting season.
I would be interested in such an updated graph for the Anarctic, not because of the sea ice itself, but because of potential feedback effect of a warmer Southern ocean on glaciers and ice shelves.
I mean a graph like this but with the current year added
https://sites.google.com/site/cryospherecomputing/warming-potential/antarctic-graphs (https://sites.google.com/site/cryospherecomputing/warming-potential/antarctic-graphs)
Title: Re: Albedo-Warming Potential
Post by: Tealight on December 12, 2016, 10:45:43 PM
That is the minima from the 2007-2016 average, right? If so, it would be interesting to see the minimum of Minima from the 1980-2000 average. The difference between the two should be significant.

Why do you want the Minimum of Minima from the 1980-2000? Wouldn't it be better to compare the average of these two time periods?

I would be interested in such an updated graph for the Anarctic, not because of the sea ice itself, but because of potential feedback effect of a warmer Southern ocean on glaciers and ice shelves.
I mean a graph like this but with the current year added
https://sites.google.com/site/cryospherecomputing/warming-potential/antarctic-graphs (https://sites.google.com/site/cryospherecomputing/warming-potential/antarctic-graphs)

To get a daily updated graph I don't have to write much code. Around 80% is already there and just has to be copied into a new file. The problem with that method is that it is very inefficient, because the calculation always starts at the 20th september I don't like it when my computer spends 10min calculating the same stuff every day over and over again.

Maybe I can spend some time next weekend and create a new logic which reads the cumulative values from the previous day and updates the file with the current day. Then the calculation time is only 3-4 seconds.
Title: Re: Albedo-Warming Potential
Post by: oren on December 12, 2016, 11:12:41 PM
Maybe ...  a new logic which reads the cumulative values from the previous day and updates the file with the current day. Then the calculation time is only 3-4 seconds.
Sounds like a good idea. Otherwise it does not scale well.
Title: Re: Albedo-Warming Potential
Post by: Tealight on December 17, 2016, 09:08:35 PM
I finished programming the new logic and graphs for daily updates. The presentation still requires some refinement, but I already uploaded them for enjoyment.

The graph looks scary, but this was partly expected when you compare a record low year with a relative high 10 year average. Maybe I should add 1986 and 1993 as two other low years for comparison.

https://sites.google.com/site/cryospherecomputing/warming-potential/antarctic-graphs
Title: Re: Albedo-Warming Potential
Post by: oren on December 18, 2016, 12:36:27 AM
The graph looks scary
It sure as hell does! I wonder if this will have any marked effect on glaciers and ice shelves as the Austral summer progresses.
Title: Re: Albedo-Warming Potential
Post by: Tealight on December 21, 2016, 12:04:42 AM
I added the years 1986/87, which has the lowest maximum and 1992/93 which still holds the lowest minimum (at least for sea ice area)

Both are quite interesting compared to recent years. 1986/7 had lots of ice near West Antarctica and very little pretty much everywhere else. 1992/3 had a more similar ice distribution to recent years, but with extreme low sea ice cover in the Weddel Sea.

https://sites.google.com/site/cryospherecomputing/warming-potential/Albedo-Warming-Overview

On the daily graph 1986/7 shows a zigzag curve because sea ice concentration could only be measured every second day.
Title: Re: Albedo-Warming Potential
Post by: Archimid on January 11, 2017, 07:18:52 PM
I was trying to visualize the effects of insolation on the shrinking arctic and I found this nifty tool. I didn't know where else to put this, but I think it is relevant in this thread.

Daylight Hours Explorer

http://astro.unl.edu/classaction/animations/coordsmotion/daylighthoursexplorer.html (http://astro.unl.edu/classaction/animations/coordsmotion/daylighthoursexplorer.html)

This app lets you select latitude and day of the year and it gives you a nifty graph.


Title: Re: Albedo-Warming Potential
Post by: charles_oil on January 12, 2017, 01:24:23 AM
Archmid - I like the daylight hour tool. 

I found: https://www.timeanddate.com/sun/ (https://www.timeanddate.com/sun/) which shows the different twilights too (Civil, Nautical and astronomical).  Sadly though you have to enter a place, country and though it has South Pole - no North Pole - no land?

Looks like the Astro one is the full daylight, but there is a large factor of partial sun during the twilight hours - I dont know how Albedo warming is affected.
Title: Re: Albedo-Warming Potential
Post by: Tealight on January 12, 2017, 08:07:30 PM
I used this app on my phone for the past 3-4 years. It's pretty great if you want to know more details like time of Sunrise and Sunset. The widget updates every minute or so.
https://play.google.com/store/apps/details?id=com.spwebgames.daylight&hl=en

During twilight the sky is illuminated, but no significant amount of sunlight reaches the surface.
Title: Re: Albedo-Warming Potential
Post by: rboyd on January 12, 2017, 08:43:04 PM
I found this paper from Taylor that seems to show that the possibility of cloud generation from open waters in the arctic is much higher in the fall than in the summer. Allowing the low albedo waters to take the heat in during the summer, then trapping the heat with more clouds in the fall.

http://onlinelibrary.wiley.com/doi/10.1002/2015JD023520/full (http://onlinelibrary.wiley.com/doi/10.1002/2015JD023520/full)

https://www.nasa.gov/feature/langley/clouds-and-sea-ice-what-satellites-show-about-arctic-climate-change (https://www.nasa.gov/feature/langley/clouds-and-sea-ice-what-satellites-show-about-arctic-climate-change)

"There's no cloud response in summer to melting sea ice, which means it is likely that clouds are not slowing down the Arctic climate change that is happening—clouds aren't really providing the expected stabilizing feedback," Taylor said. "The fact that you are melting sea ice and uncovering more ocean and the fact that clouds don't increase during summer means that they are not buffering or reducing the rate of the warming, which implies the Arctic could warm faster than climate models suggest."

So the increased energy imbalance from the reduced arctic albedo is not buffered by increased clouds, given the numbers involved this could be huge miss for the models.
Title: Re: Albedo-Warming Potential
Post by: Tealight on January 17, 2017, 06:31:39 PM
So far I've only calculated anomaly values of the Albedo-Warming Potential (AWP). This is great when comparing individual years against each other, but it doesn't directly show us which regions contribute most to the overall warming. My first calculation with absolute values are for 2016. On the cumulative map you can see that the southern Beaufort Sea had higher AWP then the always open ocean around Svalbard. It's more southern latitude is more significant then ice free conditions during the first month of the astronomical summer.

The daily animations are great to get a feeling for solar intensity. Let me know how useful you find the absolute AWP.

Link for daily animations(loads 30MB, not great for mobile users)
https://sites.google.com/site/cryospherecomputing/warming-potential/project-description/absolute-values


Some details
Snow/Ice energy absorption is approximated to 20% of that of water
Cumulative values saturate at 1200 kwh/m2 (55N)
Daily values saturate at 8kwh/m2 (60N) on 21st June
The average values are calculated over all ocean pixels and are not very relevant.

Although the solar radiation on top of the atmosphere near the north pole is highest on earth on 21st June, not all of it makes it to the surface. Due to the low solar angle the atmosphere absorbs/reflects more of the incoming radiation and the surface radiation is slightly lower then further south. This must be considered when accessing the albedo effect. (It is not a total radiation balance)
Title: Re: Albedo-Warming Potential
Post by: jdallen on January 17, 2017, 06:38:44 PM
Unsurprisingly, the Bering and Barents stand out as troubling, though parts of the Beaufort may be as well.

The Barents warming potential far and away strikes me as the most dangerous change... And this year's freezing season may be further proof of it.
Title: Re: Albedo-Warming Potential
Post by: Pi26 on January 18, 2017, 08:10:02 AM
Thanks Tealight, for me your AWP-image is the best arctic overview.
But You should additional show the numbers of Albedo-Melting-Potential in meters of ice -  would be 1/60 of Kwh numbers?
Title: Re: Albedo-Warming Potential
Post by: Rob Dekker on January 21, 2017, 09:30:17 AM
Tealight, your work received special attention in the SIPN post-season report :
https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season (https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season)

With two paragraphs, some graphics, and some pretty intelligent responses. Stuff like this :
Quote
Because the sea ice edge is generally moving northward during the spring and early summer, the edge is moving away from the regions where anomalies in the cumulative AWP are building. However, when the sea ice edge expands southward again in the fall, it can re-encounter the regions of significant cumulative AWP. Thus, there can be a connection between patterns of spring and fall sea ice concentration anomalies that is nearly independent of mid summer conditions.

Looking forward to your reply on that assessment, and keep up the great work you are doing !
Title: Re: Albedo-Warming Potential
Post by: Bill Fothergill on January 21, 2017, 02:22:28 PM
Tealight - I can only repeat Rob's sentiments. Well done.

However, may I make a small suggestion as regards your section on Freezing Degree Days. This section begins with the text...

The "Freezing Degree Days" (FDD) is a different quantification of average temperature. It combines the absolute temperature (2m) below the freezing point with the duration of the cold period.

Example:
1. Day: average Temp: -3°C
2. Day: average Temp: -5°C
3. Day: average Temp: -7°C
Total: 15°C


I may be indulging in a spot of pedantry, but the term "absolute temperature" is normally only used when one is referring to a temperature measured in Kelvin. Also, it can be helpful to a reader if one makes it very clear when one is talking about the difference between two temperatures, rather than an actual temperature. A technique for doing this is to use "3 Celsius degrees" to refer to the difference between two temperatures, and only use "minus 3 degrees Celsius" when referring to an actual temperature.

An alternative form of words could be something like...

"The "Freezing Degree Days" (FDD) is a different quantification of average temperature. Sea water typically freezes at around -1.8°C, and the "Freezing Degree" aspect refers to the amount by which  the average daily temperature (measured at a height of 2 metres above the surface) is beneath this benchmark. The cumulative FDD is simply the summation of each of these daily differences. It thus combines the temperatures below the freezing point with the duration of the cold period.

Example:
Day 1 average Temp = -3°C; Temp below freezing = 1.2 Celsius degrees
Day 2 average Temp = -5°C; Temp below freezing = 3.2 Celsius degrees
Day 3 average Temp = -7°C; Temp below freezing = 5.2 Celsius degrees

Cumulative FDD after 3 days = (1.2 + 3.2 + 5.2) = 9.6 Freezing Degree Days

(NB I am quite familiar with the NSIDC section on thermodynamic processes, as I helped edit it about 5 or 6 years ago.)

If you have not seen it already, you might be interested in this PNAS article on the observational determination of albedo decrease...

http://www.pnas.org/content/111/9/3322.full (http://www.pnas.org/content/111/9/3322.full)

On a lighter note, for your amusement, you may also want to have a look at this denialist article from about 11 years ago. The scientific rigour used in the analysis perhaps leaves a little to be desired.

http://www.warwickhughes.com/cool/cool13.htm (http://www.warwickhughes.com/cool/cool13.htm)
Title: Re: Albedo-Warming Potential
Post by: Tealight on January 21, 2017, 07:23:40 PM
Tealight, your work received special attention in the SIPN post-season report :
https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season (https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season)

With two paragraphs, some graphics, and some pretty intelligent responses. Stuff like this :
Quote
Because the sea ice edge is generally moving northward during the spring and early summer, the edge is moving away from the regions where anomalies in the cumulative AWP are building. However, when the sea ice edge expands southward again in the fall, it can re-encounter the regions of significant cumulative AWP. Thus, there can be a connection between patterns of spring and fall sea ice concentration anomalies that is nearly independent of mid summer conditions.

Looking forward to your reply on that assessment, and keep up the great work you are doing !

Well of course it received special attention. After all i volunteered to be part of the Action Team and offered my calculation to be included in the meltseason review. But my main intend to join the Action team was to promote other forcasting metrics besides extent and highlight the very low compactness of last years melting season. This is an issue we discussed heavily on the forum its time for professionals to consider other metrics than extent too. I feel with these two main inputs the SIPN if better prepared for the future. My participation is the reason why I put my real name on my maps and graphs. For scientific publications it's more appropiate. Under "Report Credits" I'm mentioned as an Action Team Member.

Quote
Action Team Members:
Gisele Arruda; Oxford Brookes University.
Ed Blockley; Polar Climate Group, Met Office Hadley Centre.
Frank Kauker; Alfred Wegener Institute for Polar and Marine Research.
Alek Petty; NASA Goddard Space Flight Center and University of Maryland.
François Massonnet; Université catholique de Louvain (UCL), Brussels and Catalan Institute of Climate Sciences (IC3, Barcelona, Spain).
Nico Sun; CryosphereComputing.

With 25 years  I'm still at the beginning of my career, unlike most of the forum members. Maybe being part of the report could help me with my future endeavours.

@Bill Fothergill
I'm not really happy with the description and calculation of FDD myself, but we would need to discuss it in another thread. There are specific reasons why I created it as I did.
Title: Re: Albedo-Warming Potential
Post by: Rob Dekker on January 22, 2017, 09:16:30 AM
That's nice, Tealight.
I am sure that you will obtain a decent job, given your commitment to science and your bold stand on issues. These are valuable traits, which are appreciated in the commercial world.

But I was asking specifically about your response to this comment in the SIPN report :
Quote
Because the sea ice edge is generally moving northward during the spring and early summer, the edge is moving away from the regions where anomalies in the cumulative AWP are building. However, when the sea ice edge expands southward again in the fall, it can re-encounter the regions of significant cumulative AWP. Thus, there can be a connection between patterns of spring and fall sea ice concentration anomalies that is nearly independent of mid summer conditions.
Title: Re: Albedo-Warming Potential
Post by: DrTskoul on January 22, 2017, 03:28:17 PM
That's nice, Tealight.
I am sure that you will obtain a decent job, given your commitment to science and your bold stand on issues. These are valuable traits, which are appreciated in the commercial world.

But I was asking specifically about your response to this comment in the SIPN report :
Quote
Because the sea ice edge is generally moving northward during the spring and early summer, the edge is moving away from the regions where anomalies in the cumulative AWP are building. However, when the sea ice edge expands southward again in the fall, it can re-encounter the regions of significant cumulative AWP. Thus, there can be a connection between patterns of spring and fall sea ice concentration anomalies that is nearly independent of mid summer conditions.

The most important thing is natural curiosity and aptitude in learning new things.... Which he has amply displaued...
Title: Re: Albedo-Warming Potential
Post by: Tealight on January 23, 2017, 12:36:45 AM
But I was asking specifically about your response to this comment in the SIPN report :
Quote
Because the sea ice edge is generally moving northward during the spring and early summer, the edge is moving away from the regions where anomalies in the cumulative AWP are building. However, when the sea ice edge expands southward again in the fall, it can re-encounter the regions of significant cumulative AWP. Thus, there can be a connection between patterns of spring and fall sea ice concentration anomalies that is nearly independent of mid summer conditions.

This section is partly my own work and I've know this exact part for over a month (The majority of the report was written in November and December. In January we did mostly polishing work). What do you expect me to reply to myself? It is just a much better wording then what I said in May 2016 on the "Quantifying albedo effect" thread.

Quote
...The model doesn't calculate if the energy is used for melting more ice or if it increases water temperature which delays refreezing and limits ice thickening in winter

Of course I'm happy that my model encouraged the SIPN network to consider forecasting fall sea ice concentrations as well. The cumulative AWP is good at showing the rough regions for low fall sea ice concentration, but there needs to be a forcing component. The Beaufort Gyre for example rotated all of the Beaufort anomalies clockwise.

Title: Re: Albedo-Warming Potential
Post by: ktonine on January 24, 2017, 03:56:27 PM
Tealight, your work received special attention in the SIPN post-season report :
https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season (https://www.arcus.org/sipn/sea-ice-outlook/2016/post-season)

Yes, Tealight, congratulations on work well done :)
Title: Re: Albedo-Warming Potential
Post by: rboyd on January 28, 2017, 08:38:12 PM
This paper on the impact of an ice free Arctic in September got mentioned in the Scribbler comments section. It assumes a worst case of 2040 as the date for an ice-free September, with no deterioration after that, which leads to a 50% cut in the global carbon budget for a 2 degree temperature rise (including overshoot and negative emissions).

http://onlinelibrary.wiley.com/doi/10.1002/2016EF000429/full (http://onlinelibrary.wiley.com/doi/10.1002/2016EF000429/full)

I am not a climate scientist, but their assumptions of (i) 2040 as the earliest possible date for an ice-free September; (ii) no worsening due to feedback - e.g. August becoming ice free; and (iii) the heat imbalance assumptions seem to be a tad conservative. If I understand the paper correctly, less conservative assumptions could more than wipe out the carbon budget. Comments from more qualified individuals would be welcome.

I do have training as an economist, and their assumptions of the ability to ramp up a fossil fuel replacement infrastructure with no bottlenecks or delays as the timeframe shrinks and scale increases means that they very significantly underestimate the costs involved. Such "frictionless" models are the standard unfortunately for the Integrated Climate Models.
Title: Re: Albedo-Warming Potential
Post by: Tealight on January 29, 2017, 02:14:24 AM
This paper on the impact of an ice free Arctic in September got mentioned in the Scribbler comments section. It assumes a worst case of 2040 as the date for an ice-free September, with no deterioration after that, which leads to a 50% cut in the global carbon budget for a 2 degree temperature rise (including overshoot and negative emissions).

http://onlinelibrary.wiley.com/doi/10.1002/2016EF000429/full (http://onlinelibrary.wiley.com/doi/10.1002/2016EF000429/full)

I am not a climate scientist, but their assumptions of (i) 2040 as the earliest possible date for an ice-free September; (ii) no worsening due to feedback - e.g. August becoming ice free; and (iii) the heat imbalance assumptions seem to be a tad conservative. If I understand the paper correctly, less conservative assumptions could more than wipe out the carbon budget. Comments from more qualified individuals would be welcome.

I do have training as an economist, and their assumptions of the ability to ramp up a fossil fuel replacement infrastructure with no bottlenecks or delays as the timeframe shrinks and scale increases means that they very significantly underestimate the costs involved. Such "frictionless" models are the standard unfortunately for the Integrated Climate Models.

Any paper that only considers carbon emmisions will fail to predict the current Arctic warming trend. Especially this and last years warming is driven by heat and moisture import from lower latitudes. Combined with low albedo in spring these effects have far more influence than CO2.

Regarding the CO2 emissions scenario projecting a decline by mid-century. This is wishful thinking even if we eliminate all fossil fuel burning. Humans have been emitting CO2 and CH4 for over 8000 years due to agriculture. The increased land use (at least in Australia and America) and intensity of agriculture since the industrial revolution should at least keep the CO2 levels at a constant high level.

I'd suggest this presentation from the American Geophysical Union (AGU) for a more detailed view on past emissions:
https://www.youtube.com/watch?v=1TOTsmqgmL8 (https://www.youtube.com/watch?v=1TOTsmqgmL8)
Title: Re: Albedo-Warming Potential
Post by: rboyd on January 31, 2017, 07:11:51 PM
Thank you Tealight. I am amazed by the amount of inertia in the general scientific community with respect to actual events in the Arctic. Given the albedo potential, the implications could completely upend the current climate policy assumptions.
Title: Re: Albedo-Warming Potential
Post by: Gray-Wolf on January 31, 2017, 07:31:14 PM
I think Mother N. is taking over our role of placing GHG aloft?

Albedo flip has fed this change by allowing ever earlier exposure of the northern permafrost/soils to the sun as ( increased?) snow ablates ever earlier.

Not only does the loss of Sea ice impact temps 1,500km away surely the early loss of snow impacts temps in a similar way?

The ever earlier loss of snow cover ( and its albedo) since the turn of the Century has increased melt forcing across the Arctic Sea ice so increasing the albedo impact but also a double whammy for the already warmed Northern lands. The run of record high temps on land areas around the Arctic Basin is no 'fluke'.

I believe we are now seeing yearly CO2 reaching record highs, even as we try and reduce our imputs, because of the warming, ongoing, across the north. This is a self reinforcing feedback loop which will remove man's CO2 emissions from the equation and lead to continued warming well beyond 2c!
Title: Re: Albedo-Warming Potential
Post by: Steven on March 01, 2017, 05:00:57 PM
New paper by Y. Zhan and R. Davies:

September sea-ice extent predicted by June reflected solar radiation

http://aip.scitation.org/doi/pdf/10.1063/1.4975531 (http://aip.scitation.org/doi/pdf/10.1063/1.4975531)

Abstract:
Quote
A significant three-month lag correlation between June top-of-atmosphere reflected solar radiation (RSR) and the subsequent September sea-ice extent (SIE) is found within the Arctic, and the predictability of September SIE is examined by both satellite observations and reanalysis datasets. The correlation coefficient between de-trended June RSR and September SIE reaches up to 0.88 for MISR, and the forecast skill of 0.36 using MERRA-2 reanalysis dataset is similar to or better than complex prediction models. Results confirm the particular importance of the early summer surface energy budget and help to explain the abrupt declines of September SIE in the past decade (2007, 2012, 2015).

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FPBNstLC.png&hash=40b1b88c2d8bca02467463eca2fee96e)

Title: Re: Albedo-Warming Potential
Post by: Buddy on March 01, 2017, 06:06:14 PM
Quote
September sea-ice extent predicted by June reflected solar radiation

For some of the more "scientifically inclined"....I have a question:

What is PRECISELY meant by "top of the atmosphere reflected solar radiation (RSR)?"

Is it:

A)  Amount of solar radiation MEASURED AT the "top of the atmosphere"?
B)  Amount of solar radiation FROM the top of the atmosphere?
C)  Other...

A non-scientific inquiring mind would like to know.... :)
Title: Re: Albedo-Warming Potential
Post by: Tealight on March 01, 2017, 07:19:43 PM
Quote
September sea-ice extent predicted by June reflected solar radiation

For some of the more "scientifically inclined"....I have a question:

What is PRECISELY meant by "top of the atmosphere reflected solar radiation (RSR)?"

Is it:

A)  Amount of solar radiation MEASURED AT the "top of the atmosphere"?
B)  Amount of solar radiation FROM the top of the atmosphere?
C)  Other...

A non-scientific inquiring mind would like to know.... :)

C)  Amount of reflected solar radiation MEASURED AT the "top of the atmosphere" (measured by satellites)

This is affected by many metrics like snow cover, sea ice, melt ponds and cloud cover. The more solar radiation is reflected from the earth the less energy is absorbed.
Title: Re: Albedo-Warming Potential
Post by: Buddy on March 01, 2017, 08:04:31 PM
Quote
C)  Amount of reflected solar radiation MEASURED AT the "top of the atmosphere" (measured by satellites)

Thanks....I assumed as much....but I don't like to assume.

Title: Re: Albedo-Warming Potential
Post by: Tealight on March 24, 2017, 11:25:44 PM
I prepared the daily updates of my AWP model for this melting season. In April I have some more time for polishing and might update all regional graphs as well. Until then you can follow the bright colour spectacle on:

https://sites.google.com/site/cryospherecomputing/warming-potential/graphs

Title: Re: Albedo-Warming Potential
Post by: oren on March 25, 2017, 08:33:56 AM
Thanks Tealight. I expect your graphs will be very busy this year.
Title: Re: Albedo-Warming Potential
Post by: Darvince on March 25, 2017, 08:42:38 AM
It tells me that permission is required to view the graphs updated for 2017.
Title: Re: Albedo-Warming Potential
Post by: Tealight on March 25, 2017, 09:04:48 AM
It tells me that permission is required to view the graphs updated for 2017.

Ah sorry I forgot to make the images public. It should be fixed now.
Title: Re: Albedo-Warming Potential
Post by: oren on March 25, 2017, 10:58:26 AM
It tells me that permission is required to view the graphs updated for 2017.

Ah sorry I forgot to make the images public. It should be fixed now.
For some reason I still find many of the images on the site appear as broken icons and are not loading. Not sure why.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 03, 2019, 01:19:03 AM
BAM! Two years have gone by without an update.

I finally have the processsing power and coding skills to take the AWP model to where I intended it to be. Instead of only calculating the anomaly of potentially absorbed solar radiation. I now calculate the raw accumulated values, the anomaly and a percentage of the current year to the maximum possible (complete Ice-free conditions). From the 1980s to 2010s this percentage has gone up from roughly 52% to 62%. Generally from August onwards the Arctic is 75% icefree and from September onwards the Arctic is 90% icefree.

Everything is now much better presented with interactive graphs and sliders to compare individual years. The regional data is already calculated, but needs even more work for proper presentation. Near-real time data for 2019 is in the works too.

Fancy new webpage:
https://cryospherecomputing.tk/awp

Still too short documentation of AWP model:
https://cryospherecomputing.tk/doc.

Title: Re: Albedo-Warming Potential
Post by: Viggy on April 03, 2019, 01:27:03 AM
Stumbled on to it while looking at your AMSR2 tab and I have to say it is absolutely beautiful in its presentation.

Please keep up the amazing work and cannot wait for the near real time data additions!
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 03, 2019, 01:45:58 AM
Stumbled on to it while looking at your AMSR2 tab and I have to say it is absolutely beautiful in its presentation.

Please keep up the amazing work and cannot wait for the near real time data additions!

Thanks Viggy, it really means a lot to me. The presentation takes up about 75% of the time, but is also the most important part.
Title: Re: Albedo-Warming Potential
Post by: oren on April 03, 2019, 05:40:57 AM
Please keep up the amazing work and cannot wait for the near real time data additions!
Indeed. I am sure many feel the same.
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 03, 2019, 12:56:43 PM
Please keep up the amazing work and cannot wait for the near real time data additions!
Indeed. I am sure many feel the same.
This person does, and like Oliver Twist, I ask for more, more, more. Tealight is a victim of his success. (Or perhaps Nico Sun is to blame).

I am sure when the regional AWP graphs come out, the cumulative change especially in the peripheral seas such as the Bering and Barents displayed from Tealight's system will be spectacular. The story is almost complete, reduced sea ice ramping up AWP, which in turn allows the seas to gobble up heat.

I wonder if we will ever have the data to show much additional heat has been swallowed by the Arctic Seas over the years from increased AWP and how much is still locked up in storage below the top few metres of the ocean.

Title: Re: Albedo-Warming Potential
Post by: Neven on April 05, 2019, 02:35:45 PM
Question from new member:

Good day,
I have been an attentive and permanent lurker for a couple of years, and really appreciate the profound knowledge and experience contributing to this forum.

There is an issue that has been nagging at the back of head for the last years, and that this open water, and more precisely the total time (days during the year) that the seas / oceans / bays that constitute the Artic Sea area have open water during the year. And also how soon there is already open water and the potential feedback that has on issue as jet stream movement, water favor, ocean currents and the like.

I understand that every year there is day by day analysis of what record will be smashed (or has been smashed) and whether there will be a BOE. I agree with the seriousness of these implications and the effects we are already witnesses around the globe.

However, if we look at 2012 when a ´perfect storm´ resulted in the current min. Arctic sea ice extent and compare this with for instance 2016. Yes the min. sea ice extent in 2016 was much higher (around 4 million km2), but there as already more open water during the period april till half july in 2016 then in 2012 (only in mid July of 2012 did the extent descrease in value in comparison to 2016). So my question would be to those that have more accumulated knowledge that I, has there been calculations on the effect that each day of open water has issues such as jet stream movement, water favor, ocean currents and the like?

And has this been expressed in some form? Perhaps km2 open water per day? Or accumulative open water during the year? Could taking the area of each of the seas be taken as a starting point.

Somehow looking at developments this year (2019) it is clear that every 1 km2 of open water that is added on a daily will start to absorb heat till it freezes over again (if it does) when winter arrives.

Appologies if the post is what long, but looking forward to feedback. Thank you Jeroen
Title: Re: Albedo-Warming Potential
Post by: ijgosse on April 05, 2019, 03:47:24 PM
Thanks Neven
Title: Re: Albedo-Warming Potential
Post by: vox_mundi on April 05, 2019, 04:09:49 PM
Perhaps one way to look at an open seas metric is to consider it the inverse of ice cover.

If its not covered by ice - it's open water.

e.g. (basin extent - ice cover) = open seas

Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 05, 2019, 04:39:42 PM
There is an issue that has been nagging at the back of head for the last years, and that this open water, and more precisely the total time (days during the year) that the seas / oceans / bays that constitute the Artic Sea area have open water during the year. And also how soon there is already open water and the potential feedback that has on issue as jet stream movement, water favor, ocean currents and the like.


....and has this been expressed in some form? Perhaps km2 open water per day? Or accumulative open water during
the year? Could taking the area of each of the seas be taken as a starting point.

For maps of ice-free days and anomalies go to Tealight's stunning website https://cryospherecomputing.tk/IceFreeDays
and for Tealight's equally stunning maps of Albedo Warming potential and anomalies thereof go to ... https://cryospherecomputing.tk/awp.html

Last year I  looked at area, ice-free days and open-water percentages by each Arctic sea and groups of seas from 1979 to 2018. If you have the patience and time, the results up to end 2018 are shown as a  series of posts starting here...
https://forum.arctic-sea-ice.net/index.php/topic,2223.msg185727.html#msg185727

But from that to calculating the  potential feedback that has on issues as jet stream movement, water favor, ocean currents and the like.? The people who do that, if ever, will get the Nobel Prize for physics and the Field Prize for Mathematics.
Title: Re: Albedo-Warming Potential
Post by: ijgosse on April 05, 2019, 08:41:10 PM
Thanks gerontocrat, these are very usefull!! And they indicate worrying developments.
kind regards Jeroen
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 07, 2019, 12:11:26 AM
The new near-real-time Albedo-Warming Potential script is programmed. If it updates tomorrow as intended I post the website link. The regional data has to wait until I structure the regional data from the previous 40 years.
Title: Re: Albedo-Warming Potential
Post by: Klondike Kat on April 07, 2019, 12:23:58 AM
Very nice tealight,
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 07, 2019, 10:48:19 AM
The regional data has to wait until I structure the regional data from the previous 40 years.

Patience, Gerontocrat, patience !

The graphs demonstrate so well that it is early melt that matters most. Although 2012 extent minimum extent was so far below all others the melt happened relatively late in the season.  2016 AWP cumulative anomaly was so much higher due to being at lowest extent in late April to late June.
Title: Re: Albedo-Warming Potential
Post by: oren on April 07, 2019, 06:41:31 PM
IIRC 2016 also had a lower area to extent ratio, which also drove the AWP.
Title: Re: Albedo-Warming Potential
Post by: FishOutofWater on April 07, 2019, 08:00:31 PM
Outstanding work, Nico. There is an added feedback that could kick in this year. All the heat is generally extracted from Pacific water before it passes into the Arctic from the Bering strait. With the exceptionally early clear out of Bering sea ice and the strong southerly winds across the strait this year, and the anomalously warm water already in the Aleutian region, we may see significant ocean heat advection from the Pacific to the Arctic this summer. That will cause a rapid wipe out of Chukchi and Beaufort sea ice if it happens and the melt out could progress into the central Arctic ocean.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 07, 2019, 10:37:28 PM
Thanks for the patience and support everybody.

Here is the AWP NRT link:
https://cryospherecomputing.tk/NRTawp

By the way I added a website icon which should be displayed next to the page name in the tab. Right now it's some melting sea ice in Beaufort Sea (2016) at super low resolution. Maybe I make a logo in the future.
Title: Re: Albedo-Warming Potential
Post by: Viggy on April 08, 2019, 12:21:39 AM
Page added to my daily favourites! Thanks again for amazing work and all the effort you've put into this!

Also, the head start the AWP anomaly has over any another year is extremely concerning for the rest of this melt season!
Title: Re: Albedo-Warming Potential
Post by: Viggy on April 09, 2019, 10:57:37 PM
Thanks for the patience and support everybody.

Here is the AWP NRT link:
https://cryospherecomputing.tk/NRTawp

By the way I added a website icon which should be displayed next to the page name in the tab. Right now it's some melting sea ice in Beaufort Sea (2016) at super low resolution. Maybe I make a logo in the future.

Some feedback - not sure if you are aware but images don’t seem to load on mobile. When I hold down on the empty space and ask to open image though, it does show up on the next tab.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 11, 2019, 12:11:44 AM
Some feedback - not sure if you are aware but images don’t seem to load on mobile. When I hold down on the empty space and ask to open image though, it does show up on the next tab.

I still have to upload daily updated images to google drive and insert a shared link into the website. (I don't know yet how put them on the github server)

Oren had the exact same problems and it had something to do with his googleaccount. Can you try opening the webpage in incognito mode?
Title: Re: Albedo-Warming Potential
Post by: Viggy on April 12, 2019, 12:37:38 PM
Some feedback - not sure if you are aware but images don’t seem to load on mobile. When I hold down on the empty space and ask to open image though, it does show up on the next tab.

I still have to upload daily updated images to google drive and insert a shared link into the website. (I don't know yet how put them on the github server)

Oren had the exact same problems and it had something to do with his googleaccount. Can you try opening the webpage in incognito mode?

Hmm yea, that’s odd but it worked perfectly fine in incognito mode!
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 18, 2019, 03:19:45 PM
The graphs already show that early melt matters. Longer time at max radiation on a larger area of open water increasing extent and depth of Arctic Seas' heating.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 20, 2019, 05:33:12 PM
Two images to show the current massive regional differences. First a Peak Watt map showing maximum solar intensity at noon. It might be important to get the initial punch to turn snow into a melt pond. The high Arctic never receives this intensity and relies entirely on imported warmth.

For daily averaged energy values the Sea of Okhotsk, closely followed by Bering Sea currently absorbs over ten times more energy than the central Arctic.

Arctic mean: 6.1 MJ/m2

Sea of Okhotsk   18.711
Bering Sea   16.264
Hudson Bay   4.977
Baffin Bay   9.695
East Greenland Sea   8.159
Barents Sea   8.567
Kara Sea   2.753
Laptev Sea   2.387
East Siberian Sea   2.462
Chukchi Sea   3.255
Beaufort Sea   2.598
Canadian Archipelago   2.75
Central Arctic   1.601
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 20, 2019, 10:23:21 PM
Two images to show the current massive regional differences. First a Peak Watt map showing maximum solar intensity at noon. It might be important to get the initial punch to turn snow into a melt pond. The high Arctic never receives this intensity and relies entirely on imported warmth.

For daily averaged energy values the Sea of Okhotsk, closely followed by Bering Sea currently absorbs over ten times more energy than the central Arctic.

Arctic mean: 6.1 MJ/m2

Sea of Okhotsk   18.711
Bering Sea   16.264
Hudson Bay   4.977
Baffin Bay   9.695
East Greenland Sea   8.159
Barents Sea   8.567
Kara Sea   2.753
Laptev Sea   2.387
East Siberian Sea   2.462
Chukchi Sea   3.255
Beaufort Sea   2.598
Canadian Archipelago   2.75
Central Arctic   1.601

The Bering and the Okhotsk Seas have had a lot of early melt.
The Greenland and Barents look as if they may be going into melt mode.
Baffin extent is pretty low.

So a double boost to AWP - low ice area + high insolation due to relatively low latitude.
Title: Re: Albedo-Warming Potential
Post by: oren on April 20, 2019, 11:28:47 PM
Tealight than you again for your amazing cryosphere computing resources. I keep wondering how the extra added insolation, the AWP anomaly, affects the melting  season. It is certain that extra AWP in the inner Arctic basin has a significant effect. 2016 was a great example, where the extra AWP in April and May was the background that enabled the GAC in August, and also delayed the freezing season significantly, so that winter 2017 saw the lowest volume by far on record. All this despite the cloudy weather in June and July 2016 that prevented a new September extent record.
I am also quite confident that AWP anomalies in connected peripheral seas, such as the Bering and the Barents, affect the melting season progress in the central Arctic, where the minimum is set. However, I believe AWP anomalies in the following seas do not have much effect on September minima, though  they do contribute to general AGW:
Hudson Bay - far and geographically disconnected  from the central arctic, melts out anyway every summer.
Sea of Okhotsk - same as above.
Gulf of St. Lawrence - same as above.
Baffin Bay - downstream (in terms of main currents) of the CAA and central Arctic, melts anyway every summer. Its gained heat flows south.
Greenland Sea - downstream of the central Arctic, its ice in September is ice that was exported from the central Arctic late in the melting season. Its gained heat flows south.

I personally would be happy to see a "central basin and connected seas" cumulative AWP anomaly graph, excluding the seas listed above, in addition to the pan-arctic graph.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 21, 2019, 11:58:18 AM
Oren I just finished summarizing the regional data. The Bering Sea and Beaufort Sea are already very close to icefree. If I do another central Arctic Graph for the pack ice region then they have to drop as well. In my view the Barents Sea is just like Greenland Sea, mostly for export of central Arctic Ice. The Bering Sea is too far south to affect the Central Arctic, at most it affects southern Chukchi Sea but not more. 2012 has shown that the Pacific side of the Arctic can get a huge melt even with a record bad Bering Sea melt.


Title: Re: Albedo-Warming Potential
Post by: oren on April 21, 2019, 12:32:32 PM
Thanks Tealight. My thinking about the Bering and Barents is that they are partly upstream of the central Arctic in terms of currents and sometimes winds, but certainly the effect is much lower than the inner regions. I'll be perfectly happy with a central Arctic graph without them.
Title: Re: Albedo-Warming Potential
Post by: Tealight on April 27, 2019, 07:04:48 PM
Before working on all region graphs I created another section for the High Arctic. This one should be more useful for determining the record low in September. It only includes the following regions: Kara Sea, Laptev Sea, East Siberian Sea, Chukchi Sea, Beaufort Sea, Canadian Archipelago, Central Arctic.

For the high Arctic 2012 still holds the record high followed by 2016 in second and 2007/2011 tied in third. The far higher average ice cover also significantly increases the gap to a completly ice-free state. On one hand the 2010s just reach 40% of the ice-free conditions compared to 61% for the whole Arctic. But on the other hand the 2010s absorb 32% more than the 1980s. For the whole Arctic it's just 15% more. So the last ten years really impacted the high latitudes more than the lower ones.

https://cryospherecomputing.tk/awp

Note: Before doing this recalculation I increased the ice albedo from 80% to 85% relative to ocean albedo. This is more in line with the values I measured from satellite images. The result is slighly lower absolute values, but hardly any change to anomaly values. The near-real time data will be updated tomorrow.
Title: Re: Albedo-Warming Potential
Post by: oren on April 27, 2019, 07:45:24 PM
Thanks a lot Tealight.
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on April 27, 2019, 08:04:46 PM
Here are 2 area graphs,

The High Arctic 7 seas as defined by Tealight,

All 14 Arctic Seas per NSIDC.

As you can see, as far as the High Arctic is concerned, melting has not really started yet.
It also shows that the summer melt produced relatively steeper decline in these central seas.
Title: Re: Albedo-Warming Potential
Post by: kiwichick16 on April 28, 2019, 06:55:03 AM
losing  a million  sq kms per decade @ at the annual minimum in September.......at that rate the Arctic will be ice free sometime in the 2030's  ....if not before
Title: Re: Albedo-Warming Potential
Post by: Stephan on April 28, 2019, 01:02:03 PM
Tealight - thanks a million for all the work you've done
Gerontocrat - thanks for the ice cover charts to support Tealight's evaluation.

Two 'likes' earned
Title: Re: Albedo-Warming Potential
Post by: Tealight on May 01, 2019, 01:05:08 AM
Just in time before the May melt ponds start I created the regional anomaly charts. Just like last year almost all of the early accumulated AWP anomaly comes from the Bering Sea, but this year none of the regions is in the negative.

https://cryospherecomputing.tk/NRTawp
Title: Re: Albedo-Warming Potential
Post by: dosibl on May 02, 2019, 04:54:43 PM
No surprise that we're tracking to get a similar anomaly in the Bering as last year, iirc last years ~250 mj/m2 was basically double any prior year.

Tealight, my understanding of the 'potential' part of AWP is that the calculation doesn't account for weather, correct? A cloudy season and a sunny season with similar extent would produce similar AWP numbers but would experience different actual warming?
Title: Re: Albedo-Warming Potential
Post by: oren on May 03, 2019, 12:52:15 AM
No surprise that we're tracking to get a similar anomaly in the Bering as last year, iirc last years ~250 mj/m2 was basically double any prior year.

Tealight, my understanding of the 'potential' part of AWP is that the calculation doesn't account for weather, correct? A cloudy season and a sunny season with similar extent would produce similar AWP numbers but would experience different actual warming?
2019 is actually tracking somewhat higher, at 200 instead of 175.

My understanding of the 'P' is the same.
Title: Re: Albedo-Warming Potential
Post by: Tealight on May 03, 2019, 02:21:56 AM
No surprise that we're tracking to get a similar anomaly in the Bering as last year, iirc last years ~250 mj/m2 was basically double any prior year.

Tealight, my understanding of the 'potential' part of AWP is that the calculation doesn't account for weather, correct? A cloudy season and a sunny season with similar extent would produce similar AWP numbers but would experience different actual warming?

You are right that it doesn't account for weather and doesn't calculate actual warming. The data presented here is just a model to rank years against each other instead of a daily or monthly minimum number. It also quantifies the actual surface albedo change in the Arctic. However, the underlying physics are good enough for real applications. Maybe I can give more information tomorrow.
Title: Re: Albedo-Warming Potential
Post by: Darvince on May 05, 2019, 07:11:02 PM
I note that 2016 despite its very strong early start ended up with a lower AWP anomaly than 2012 in the high Arctic. I guess that's the power of cloudy weather for you.
Title: Re: Albedo-Warming Potential
Post by: Tealight on May 05, 2019, 08:27:26 PM
Very popular here are the sea ice minimum and maximum polls guessing the correct sea ice extent in millions of square kilometer. A more scientific oriented version of it is the Sea Ice Prediction Network: https://www.arcus.org/sipn (https://www.arcus.org/sipn)
This year was the second time they made a trial run to forecast the Antarctic summer minimum and I participated (as Nico Sun) with a forecast model derived from this Albedo-Warming Potential model. The underlying physics are the same. The major difference is that instead of accumulating an energy value in a grid cell, this energy is used to calculate the sea ice thickness loss. Additionally I added an outgoing infrared radiation variable to get an actual energy balance.

With the post season report released I can proudly claim victory not only in overall area values, but also on a regional scale with the lowest error over the entire 3 month forecasting period. This is in part thanks to the real world usefulness of the AWP model and in part due to the submission deadline of 1st December. Some other team's can only run their models at the beginning of every month and had to use October data for their model initialization. I attached the two most relevant figures, but recommend to read the whole report.

Full 2018-2019 post season report
http://www.climate.be/users/fmasson/SIPN-South_2018-2019_postseason.pdf (http://www.climate.be/users/fmasson/SIPN-South_2018-2019_postseason.pdf)

General SIPN south website
http://acecrc.org.au/sipn-south/ (http://acecrc.org.au/sipn-south/)


Sea Ice Loss Formula of the forecast model:

Ed = MJ_inlat,day x (1 - SIC) - MJ_out
z = Ed / Efusion

Ed = Melt energy per day
MJ_in = incoming solar radiation per m2
MJ_out = outgoing infrared emmision per m2
SIC = sea ice concentration
z = thickness loss in m
Efusion = Enthalpy of fusion per m3
Title: Re: Albedo-Warming Potential
Post by: magnamentis on May 05, 2019, 08:34:10 PM
I note that 2016 despite its very strong early start ended up with a lower AWP anomaly than 2012 in the high Arctic. I guess that's the power of cloudy weather for you.

i think that's because there was way more open water in the CAB in 2012 at the end of the melting seasons hence AWP is somehow logically higher under those conditions and will be again once such a state has been reached
Title: Re: Albedo-Warming Potential
Post by: oren on May 05, 2019, 08:55:52 PM
Well done Tealight/Nico!
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on May 05, 2019, 09:39:44 PM
So Nico Sun gets the medal. Will Tealight get upset ?
Will they send rude letters to the science journals about each other?

And by the way, now the regional Arctic models are up and running, with the key separating out of the high Arctic seas, will he or him or they enter the lists on foreasting the Arctic sea ice minimum?

Tealight, you derive AWP using sea ice area and then use this as a basis to calculate the energy available to reduce sea ice thickness ? How do you translate reduced thickness into resulting sea ice area and extent? A sea might have remaining ice piled up in one area  or spread out giving a higher extent value due to varying winds and currents?

Ps: An impressive piece of work. What with the work on glaciers as well - stunning.
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on May 05, 2019, 10:11:24 PM
So Nico Sun gets the medal. Will Tealight get upset ?
Will they send rude letters to the science journals about each other?

And by the way, now the regional Arctic models are up and running, with the key separating out of the high Arctic seas, will he or him or they enter the lists on foreasting the Arctic sea ice minimum?

Tealight, you derive AWP using sea ice area and then use this as a basis to calculate the energy available to reduce sea ice thickness ? How do you translate reduced thickness into resulting sea ice area and extent? A sea might have remaining ice piled up in one area  or spread out giving a higher extent value due to varying winds and currents?

Ps: An impressive piece of work. What with the work on glaciers as well - stunning.
Tealight and Nico Sun are the same person...
Title: Re: Albedo-Warming Potential
Post by: Tor Bejnar on May 05, 2019, 11:17:48 PM
Ever have an agrument all by yourself?
 ::) :-\
Title: Re: Albedo-Warming Potential
Post by: Tealight on May 05, 2019, 11:18:23 PM
Thanks everyone. I can confirm it feels good to beat major international organisations like NASA, MetOffice and ecmwf.

Tealight, you derive AWP using sea ice area and then use this as a basis to calculate the energy available to reduce sea ice thickness ? How do you translate reduced thickness into resulting sea ice area and extent? A sea might have remaining ice piled up in one area  or spread out giving a higher extent value due to varying winds and currents?

Technically I keep track of two sea ice concentration values. One to calculate the melt (using SIC from previous years) and another calculated from thickness. The second one is the final model output. The additional thickness step makes the model more robust against flashes of low SIC like short term melt ponds.

For the Antarctic I used the following formula to get the best results:
SIC(%) = (Thickness(m)^1.3) / 0.0155

Thickness(m)   SIC value (%)
1.4   100
1.25   86
1   65
0.75   44
0.5   26
0.25   11
0   0

anything over 1.4m stays at 100% SIC.
Title: Re: Albedo-Warming Potential
Post by: PaulPassmore on May 10, 2019, 04:17:20 PM
Quote
No surprise that we're tracking to get a similar anomaly in the Bering as last year, iirc last years ~250 mj/m2 was basically double any prior year.

Tealight, my understanding of the 'potential' part of AWP is that the calculation doesn't account for weather, correct? Maybe this website https://edubirdie.com/math-problem-solver (https://edubirdie.com/math-problem-solver) could do this calculation? A cloudy season and a sunny season with similar extent would produce similar AWP numbers but would experience different actual warming?

It's weird that calculations are so different every year. It seems like main rules are changing all the time.
Title: Re: Albedo-Warming Potential
Post by: b_lumenkraft on May 11, 2019, 07:37:13 AM
It's weird that calculations are so different every year. It seems like main rules are changing all the time.

Well, it's not that weird, this is a highly complex system after all.

Hello and welcome to the forum Paul.
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on May 11, 2019, 12:49:07 PM
It's weird that calculations are so different every year. It seems like main rules are changing all the time.

Well, it's not that weird, this is a highly complex system after all.

Hello and welcome to the forum Paul.
The basic laws of physics underlying the calculations do not change. The rules for calculations only change if studies have proved better algorithms. When that happens, the new calculations are applied to all previous data to ensure the record is consistent.

What does change is the weather and behaviour of the oceans that can completely change the pattern of sea ice melt and freeze sea by sea.

Chaos Theory
Edward Lorenz was an early pioneer of the theory. His interest in chaos came about accidentally through his work on weather prediction in 1961.

Welcome to chaos, Paul.
Title: Re: Albedo-Warming Potential
Post by: jai mitchell on May 16, 2019, 08:36:15 PM
any analysis of the current impact of albedo forcing due to seasonal sea ice loss during the satellite period should be compared with regional ice loss impacts not arctic basin impacts,  this is due to the variable seasonal solar radiation which maxes at the summer solstice and the retreat of sea ice from the periphery during this time.

The only good study I have found on this was looking at the Beaufort Sea by NASA

https://earthobservatory.nasa.gov/images/84930/the-arctic-is-absorbing-more-sunlight

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When averaged over the entire Arctic Ocean, the increase in absorbed solar radiation is about 10 Watts per square meter. This is equivalent to an extra 10-watt light bulb shining continuously over every 10.76 square feet of Arctic Ocean for the entire summer. Regionally, the increase is even greater, Loeb noted. Areas such as the Beaufort Sea, which has experienced the some of the most pronounced decreases in sea-ice coverage, show a 50 watts per square meter increase.

This is necessary because future sea ice loss impacts during the summer will grow to over 5-fold of the current forcing (determined to be some percentage of 25% of total CO2 forcing around at 2014. 

This large regional forcing will produce rapid changes in the Arctic, especially as we move toward June 21 Summer sea ice loss.

Title: Re: Albedo-Warming Potential
Post by: iceman on May 18, 2019, 03:55:04 PM
any analysis of the current impact of albedo forcing due to seasonal sea ice loss during the satellite period should be compared with regional ice loss impacts not arctic basin impacts,  this is due to the variable seasonal solar radiation which maxes at the summer solstice ....

At the Arctic circle (latitude of southern Chukchi), insolation reaches 90% of its peak value around this time of year. Open water, clear skies... not good.

We can expect some rotation of ice from Beaufort into Chukchi, which would confound the regional impact of albedo forcing on a time scale of a melting season.
Title: Re: Albedo-Warming Potential
Post by: gerontocrat on May 18, 2019, 05:08:54 PM
A fella called Tealight, with the help of his Avatar Nico Sun, has done the biz at https://cryospherecomputing.tk/NRTawp. It is updated daily and is wunderbar. Note he has analyses for the Arctic in total, individual seas, and "The High Arctic" (=the seven seas of the Arctic Ocean itself)

Using his AWP data combined with lots of other maths re sea ice SST's etc, he has already smashed the opposition on forecasting Antarctic Sea Ice. I am hoping to see if he is going attempt the same for the Arctic.

Examples of graphs and maps attached.
Title: Re: Albedo-Warming Potential
Post by: Tealight on June 08, 2019, 01:07:52 AM
The recent warm temperatures over the central Arctic did not result in a significant albedo drop. I suspect the peak sunshine intensity this far north is just too low to force widespread meltponding. Without imported heat from the south it just stays an iceblock. It's like trying to melt some metal in a common household oven. You can heat it for a few days, but you never melt the surface unlike a few minutes in a furnace.

The absence of importet heat means 2016 won the battle for first place and in a few days begins the dominance of 2012 until the end of the melting season.
Title: Re: Albedo-Warming Potential
Post by: FishOutofWater on June 08, 2019, 01:29:05 AM
The largest thermal anomalies in May were in the Canadian side of the Arctic where it is normally so cold that the average temperature was below freezing for sea ice. This explains much of what happened to keep melt pond formation down.

However, sea ice transport towards the Fram and Nares straits has been exceptionally high compared to recent years. The melt season may have surprises ahead but we must remember than 2012 was exceptional.

Thanks Tealight for your valuable contribution.
Title: Re: Albedo-Warming Potential
Post by: dosibl on June 10, 2019, 08:16:23 PM
The Beaufort seems to have exceeded the Y axis on the daily anomaly graphs, not sure if that value can be easily changed or if this would be problematic for older graphs which have the current Y axis maximum.
Title: Re: Albedo-Warming Potential
Post by: Tealight on June 15, 2019, 10:18:05 PM
After a short drop 2019 is back to challenge 2016 for 1st place in accumulated AWP. All thanks to the recent melt pond surge. But the Beaufort Sea still leads all regions by a wide margin because open ocean is darker than melt ponds.

The Beaufort seems to have exceeded the Y axis on the daily anomaly graphs, not sure if that value can be easily changed or if this would be problematic for older graphs which have the current Y axis maximum.

It was an easy fix.
Title: Re: Albedo-Warming Potential
Post by: oren on June 15, 2019, 10:41:49 PM
Thanks for the update Tealight.
With most of the negative anomalies found in Hudson Bay and in the Kara-Barents-Fram complex, both regions prone to imminent melt, that gives the overall positive anomaly an added twist.
Title: Re: Albedo-Warming Potential
Post by: bbr2314 on June 16, 2019, 02:23:08 AM
Thanks for the update Tealight.
With most of the negative anomalies found in Hudson Bay and in the Kara-Barents-Fram complex, both regions prone to imminent melt, that gives the overall positive anomaly an added twist.
I have been harping on this. The only "good" anomalies are in regions that will melt out in July-August anyways. We know Slater's graph has issues but even his graph shows 5.89M KM^2 extent remaining as of 8/4, WITH a major part of HB remaining that is unlikely to be there at that point (or will be gone shortly thereafter).

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fcires1.colorado.edu%2F%7Easlater%2FSEAICE%2Fthis_year_map.png&hash=c84cb3a881263b10f1b12e866b843229)

This should result in an easy cinching of the record for most of August, IMO, and probably September as well. If not the record, which I suspect it will be, this season will easily rank alongside 2012 + 2016.
Title: Re: Albedo-Warming Potential
Post by: Tealight on June 16, 2019, 02:43:51 AM
You are right. All negative anomaly isn't in regions that affect the central Arctic.

Despite currently eastern winds in the Beaufort Sea, the ocean current aka Beaufort gyre still pushes the warm water west/north-west. In July and August we should see strong bottom melt in the central Arctic north of Wrangel Island. I don't think it quite reaches the North Pole.

I predict the September minimum to match 2012/2016 if AWP continues this way or a mean 2010s area/extent if conditions go worse.
Title: Re: Albedo-Warming Potential
Post by: Sterks on June 16, 2019, 09:56:01 PM
Very popular here are the sea ice minimum and maximum polls guessing the correct sea ice extent in millions of square kilometer. A more scientific oriented version of it is the Sea Ice Prediction Network: https://www.arcus.org/sipn (https://www.arcus.org/sipn)
This year was the second time they made a trial run to forecast the Antarctic summer minimum and I participated (as Nico Sun) with a forecast model derived from this Albedo-Warming Potential model. The underlying physics are the same. The major difference is that instead of accumulating an energy value in a grid cell, this energy is used to calculate the sea ice thickness loss. Additionally I added an outgoing infrared radiation variable to get an actual energy balance.

With the post season report released I can proudly claim victory not only in overall area values, but also on a regional scale with the lowest error over the entire 3 month forecasting period. This is in part thanks to the real world usefulness of the AWP model and in part due to the submission deadline of 1st December. Some other team's can only run their models at the beginning of every month and had to use October data for their model initialization. I attached the two most relevant figures, but recommend to read the whole report.

Full 2018-2019 post season report
http://www.climate.be/users/fmasson/SIPN-South_2018-2019_postseason.pdf (http://www.climate.be/users/fmasson/SIPN-South_2018-2019_postseason.pdf)

General SIPN south website
http://acecrc.org.au/sipn-south/ (http://acecrc.org.au/sipn-south/)


Sea Ice Loss Formula of the forecast model:

Ed = MJ_inlat,day x (1 - SIC) - MJ_out
z = Ed / Efusion

Ed = Melt energy per day
MJ_in = incoming solar radiation per m2
MJ_out = outgoing infrared emmision per m2
SIC = sea ice concentration
z = thickness loss in m
Efusion = Enthalpy of fusion per m3
Did you submit to the SIPN? The site seems abandoned, no way to know the participants of course...
Title: Re: Albedo-Warming Potential
Post by: Tealight on June 17, 2019, 06:26:31 PM
Did you submit to the SIPN? The site seems abandoned, no way to know the participants of course...

I did submit my forecast. The June Report is scheduled to be released on the 21 June 2019. It seems like the whole ARCUS (Arctic Research Consortium of the United States) website was taken offline, not just SIPN.
Title: Re: Albedo-Warming Potential
Post by: LDorey on June 17, 2019, 11:14:34 PM
So I responded regarding these awesome graphs in the main thread wrt cloud cover and it got me thinking about cloud cover and satellites, surely someone must be getting a decent track record of how cloudy it is up in the arctic (or the whole planet for that matter), and i tracked down these links, I couldn't create an account, but if you're looking for a source of cloud cover info to relate back to the albedo stuff...

http://www.cloudsat.cira.colostate.edu/

http://www.cloudsat.cira.colostate.edu/community-products/arctic-observation-and-reanalysis-integrated-system